''Sternoptyx'' is an

ocean The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

which belongs in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Sternoptychidae. This is the type genus of the Sternoptychidae, as well as the

marine hatchetfish Marine hatchetfishes or deep-sea hatchetfishes are small deep-sea mesopelagic ray-finned fish of the stomiiform subfamily Sternoptychinae. They should not be confused with the freshwater hatchetfishes, which are not particularly closely relate ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Sternoptychinae. ''Sternoptyx'' have silvery, high, and laterally compressed bodies and large, non-telescopic eyes. They are all relatively small, with even the largest species (''S. pseudobscura'' and ''S. pseudodiaphana'') not exceeding

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

Species

There are currently four recognized species in this genus: * ''

Sternoptyx diaphana ''Sternoptyx diaphana'', the diaphanous hatchetfish, is a species of deep sea ray-finned fish in the family Sternoptychidae. It is the type species of the genus ''Sternoptyx'', and was first described by the French naturalist Johann Hermann in ...

'' Hermann, 1781 (Diaphanous hatchetfish) * '' Sternoptyx obscura''

Garman Garman is a surname or first name. Notable people with the name include: Sports * Ann Garman, All-American Girls Professional Baseball League player * Judi Garman (born 1954), American softball coach * Mike Garman (born 1949), American baseball pla ...

, 1899 * '' Sternoptyx pseudobscura'' R. C. Baird, 1971 (Highlight hatchetfish) * '' Sternoptyx pseudodiaphana'' Borodulina, 1977 (False oblique hatchetfish)

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of this genus show that they have existed at least since the Early Oligocene, about 30

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

. (2002): 'Sternoptyx'' ''In:'' A compendium of fossil marine animal genera. ''Bulletins of American Paleontology'' 364: 560
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References

Sternoptychidae Extant Rupelian first appearances Ray-finned fish genera Taxa named by Johann Hermann Rupelian genus first appearances {{Stomiiformes-stub